1. Field of the Invention
The present invention relates to a divided stator and a manufacturing process for a divided stator used in a rotating electric apparatus, and more specifically, to a manufacturing process that can rigidly connect pole pieces by a simple operation while maintaining accurate positioning of the pole pieces.
2. Discussion of the Related Art
In a rotating electric apparatus, in order to simplify coil winding of the stator, a divided stator has been proposed in which a plurality of pole piece laminates are arranged in a ring, and the inside pole portions of pole piece laminates are connected with synthetic resin, etc. to form an iron core. After winding coil between slots of the iron core, the iron core is fitted into a cylindrical outer ring yoke (see Japanese Utility Model Application Laid-open No. Hei 2-44848 (1990) and Japanese Patent Application Laid-open No. Hei 4-58746 (1992)).
On the other hand, in order to position pole pieces accurately with respect to each other and to ensure durability and reliability of the stator, the applicant of the present invention has proposed a process for manufacturing an iron core by integrally forming an iron core blank in which a plurality of pole pieces are arranged in the form of a ring. A bridge portion is formed between adjoining ends of the inner circumferential tip of each pole piece protruding from the inner circumferential end inwards or between adjoining ends of the outer circumferential tip protruding from the outer circumferential end outwards. This is followed by laminating a plurality of iron core blanks and fixing them to each other, fitting them into forming dies to connect them with a synthetic resin material, and then cutting the bridge portion protruding either inwards or outwards (see Japanese Patent Application No. Hei 4-117035).
However, in the above-mentioned manufacturing process, since a plurality of iron core blanks are stacked and inserted in forming dies and portions of the pole pieces are connected with a synthetic resin material, a complicated process for inserting iron core blanks and injecting synthetic resin material are required. Since the pole pieces are connected by covering them with synthetic resin, the connection strength between adjoining pole pieces is low, and the pole piece connecting operation and bridge portion cutting operation must be carried out separately, which complicates the process.